Improvement in piano-stool screw



J. KRIEG.

Screw for Piano Stools.

No. 85,454. v Patented Dec. 29, 1868.

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JULIUS KRIEG, OF "NEW YORK, N; Y.

Letters Patent No. 85,454, dated December 29, 1868.

IMPROVEMENT IN PIANO-STOOL SCREW.

The Schedule referred to in these Letters Patent and making part of the 88128- To all whom it may concern:

Be it known that I, JULIUS KRIEG, ofthe city, county, and State of New York, have invented a new and improved Screw for Piano-Stools, 850 and I do hereby (leclare the following to be a full, clear, and exact'description thereof, which will enable those skilled in the art to make and use the same, reference being bad to the accompanying drawing, forming part of this specification, in which drawing- Figure 1 is an elevation of my improved screw, showing the nut that is connected with the pillar of the stool.

Figure 2 is a top or plan-view of the cross or head.

Similar letters indicate corresponding parts.

My invention relates to screwsfor piano-stools, and is also applicable for other purposes.

In constructing my improved screw, I prepare a cylinder of wood, of suitable length and diameter for the purpose, and cut or form thereon a spiral groove or sunken thread, which may extend from end to end of the cylinder. In the sunken screw-thread or groove I wind a wire of suitable diameter, fastening its ends in a secure manner.

The depth of the spiral groove may be about onehalf the diameter of the wire, so that the portion of the wire which projects beyond the periphery of the cylinder, shall form a screw-thread, which will receive and operate with a nut, 'in the usual manner.

The cross or head at the top of the screw, which serves to connect it with the seat of the stool, is fastened to the cylinder or shank of the screw in a peculiar manner, as is hereinafter described.

The letter A designates the cylinder, on which the screw is formed. On this cylinder I out a spiral groove, B, of suitable depth, according to the diameter or size of the screw-thread required, andof such a pitch as is desired. In the groove B, I wind awire, G, of metal, or other suitable material, fastening said wire at or near the ends of the spiral groove.

The diameter of the wire is such that it will fill the. groove and proj ect beyond the periphery of the cylinder A far enough to form thereon a raised spiral head or screw-thread, in the manner illustrated in the drawing.

The letter D designates the cross or head at the top of the screw, consisting, in this example, of four arms E, arranged atright angles to each other, having at their intersections a hub, into or through the centre of which the cylinder or body of the screw is inserted, as is seen in fig. 2. Said figure also showsthe, upper end of the wire 0, where itis exposed at the end of the screw or cylinder, at which place it is filed off smooth, so as to be even with the end of the hub.

In order to fasten the hub and the cross upon and to the screw or cylinder A, so that they cannot be moved 'or turned thereon, I insert through the sides of the hub, and into the screw or cylinder, pins G, which are placed at such points as to penetrate the screw or cylinder between adjacent coils of the wire, in oblique directions, and in sufiicientnumbers as effectually to lock the hub of the cross upon the screw or cylinder, and render it incapable of moving thereon, and at the same time these pins serve to secure the wire forming the coil firmly in position.

In preparing the hub, I tap the same, so that it can be turned on the screw or cylinder, and brought to its proper position thereon, according to the length 'required for the screw when completed.

- The fcross audits hub are secured to the seat or body of the piano-stool in any suitable manner, and a nut, H, which is fixed in or upon the pillar or lower part of the stool, serves to connect the threaded cylinder with'said pillar, in such a manner that the seat of the stool can be raised or lowered thereon at pleasure.

I By means of my invention, among other advantages, I produce a screw capable of much wear, and easy of operation, while the cost of construction is small compared with the screws now used, which are made wholly of metal.

I am aware that it is not new to'form screws by coiling a small wire around a larger straight Wire, as a nucleus, but this forms no part of my invention. I disclaim all screws formed with a metallic core, around which a metallic thread is coiled.

Having thus described my invention,

What I claim as new, and desire to secure by Let ters Patent, is

1. A screw, formedby first spirally grooving a wooden cylinder, and then coiling a wire, 0, in said groove, as herein described, as-a new article of manufacture.

2. The piano-stool screw, consisting of a wooden cylinder, A, spirally grooved, and having a wire thread, 0, coiled in said groove, the screw being provided with a cross, D E, for the seat, secured to the upper end by pins G, as shown, whereby the wire 0 is held in place,

as herein described.

JULIUS KRIEG."

Witnesses:

W. HAUFF, E. F. Knsrnnnnsnn. 

